A fresh coronavirus outbreak in Beijing has prompted authorities to test millions of people and impose new measures two weeks ahead of the opening of the Winter Olympics.
The move comes as Chinese officials on Monday lifted a month-long lockdown on the northern city of Xi’an and its 13 million residents.
Despite falling case numbers, pandemic controls have been stepped up ahead of the Olympics, where all participants must be tested before and after their arrival in Beijing.
In the capital, the two million residents of Fengtai district underwent testing following the discovery of more than three dozen cases in the city.
Targeted testing was being conducted at residential communities in six other districts.
The government told people in areas of Beijing deemed at high risk for infection not to leave the city after 25 cases were found in Fengtai and 14 elsewhere.
Residents lined up on Sunday on snow-covered pavements in freezing weather for testing.
The Beijing Municipal Health Commission also said on Sunday that anyone who had purchased medicine for fever, cough and other infections within the past two weeks would be required to take a Covid-19 test within 72 hours, the state-owned Global Times newspaper reported.
The Olympics are being held under strict controls that are meant to isolate athletes, staff, reporters and officials from residents.
Athletes are required to be vaccinated or undergo a quarantine after arriving in China.
The announcement by the city of Xi’an on Monday followed the restart of commercial flights from the city over the weekend.
The major tourism centre and former imperial capital, famed as the home of the Terracotta Warrior statue army, struggled to get food to some residents in the early days of the lockdown, after people were confined to their homes.
Xi’an has been a cornerstone of the ruling Communist Party’s “zero tolerance” strategy towards Covid-19 that mandates lockdowns, travel restrictions and mass testing whenever a case is discovered.
The city is about 1,000 kilometres (600 miles) south-west of Beijing, where the Olympics open on February 4.
Access to Xi’an was suspended on December 22 following an outbreak attributed to the Delta variant of coronavirus.
Other outbreaks prompted the government to impose travel bans on a number of cities, including the port of Tianjin, about an hour from Beijing.
The stiff regulations are credited with preventing major nationwide outbreaks and China has reported relatively few cases of the highly infectious Omicron variant.
China on Monday reported just 18 new cases of local infection, including six in Beijing.
The country has 2,754 current cases of infection and has reported a total of 105,660 cases of Covid-19 with 4,636 deaths.
A number of nearby provinces reported cases linked to the outbreaks in the capital, including Shandong and Hebei provinces.
The city of Shenyang in Liaoning province reported a positive test result in a person with no symptoms, also related to the Beijing clusters.
Organisers on Monday said 39 people among the 2,586 athletes, team officials and others who arrived after January 4 had tested positive for the virus upon landing at Beijing airport.
Another 33 people who had already entered the bubble isolating participants from the general public later tested positive, the organising committee said on its website.
The statement did not identify those who tested positive other than to say they were “outside stakeholders”, a term that excludes athletes or coaches.
China mandates 21 days of quarantine for people arriving from abroad, but had waived that for those coming for the Olympics on condition they tested negative for the virus.